What is TMS?

Brain cells communicate with each other and the body using electrical signals. Scientists can investigate what some areas of the brain do by stimulating them with electricity. This could once only be done only during brain surgery, as applying electricity directly to the scalp is very painful. Now, a technique called transcranial magnetic stimulation (TMS), uses magnetism to stimulate areas of brain without causing pain and while the patient is conscious.

Until a few years ago, electrically stimulating the brain was only possible during brain surgery.

What is TMS used for?

Scientists hope to use TMS to investigate illnesses such as schizophrenia, and also to see how the brain rewires after damage such as stroke. Doctors now use TMS to diagnose diseases that affect the communication between brain and body, such as multiple sclerosis. It also seems to be effective in treating some forms of depression.

How does TMS work?

Doctors can use TMS to find out how different parts of the brain are wired together. To carry out TMS, a magnetic coil is held over a person's head. A rapidly changing magnetic field passes through the skull, and causes small electric currents to flow in parts of the brain. TMS can be used to produce effects by disrupting normal brain activity - such as making muscles twitch.